refactor: refactor in golang

Author: geekdada

.prettierrc.js

@@ -0,0 +1,9 @@
+module github.com/geekdada/steam-otp
+
+go 1.15
+
+require (
+	github.com/funny/binary v0.0.0-20151214134736-b048dcb0f179
+	github.com/jessevdk/go-flags v1.4.0
+	github.com/manifoldco/promptui v0.8.0
+)

go.mod

@@ -0,0 +1,23 @@
+github.com/chzyer/logex v1.1.10/go.mod h1:+Ywpsq7O8HXn0nuIou7OrIPyXbp3wmkHB+jjWRnGsAI=
+github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e h1:fY5BOSpyZCqRo5OhCuC+XN+r/bBCmeuuJtjz+bCNIf8=
+github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5PlCu98SY8svDHJxuZscDgtXS6KTTbou5AhLI=
+github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=
+github.com/funny/binary v0.0.0-20151214134736-b048dcb0f179 h1:i+sPtS01ifIDV7EP+GJMwqermatkNjzgDbEzYhv36IY=
+github.com/funny/binary v0.0.0-20151214134736-b048dcb0f179/go.mod h1:0NTmabtiIl9h02d11pe02xPTFvnH5K56lrE0cpeq3eI=
+github.com/jessevdk/go-flags v1.4.0 h1:4IU2WS7AumrZ/40jfhf4QVDMsQwqA7VEHozFRrGARJA=
+github.com/jessevdk/go-flags v1.4.0/go.mod h1:4FA24M0QyGHXBuZZK/XkWh8h0e1EYbRYJSGM75WSRxI=
+github.com/juju/ansiterm v0.0.0-20180109212912-720a0952cc2a h1:FaWFmfWdAUKbSCtOU2QjDaorUexogfaMgbipgYATUMU=
+github.com/juju/ansiterm v0.0.0-20180109212912-720a0952cc2a/go.mod h1:UJSiEoRfvx3hP73CvoARgeLjaIOjybY9vj8PUPPFGeU=
+github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
+github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/lunixbochs/vtclean v0.0.0-20180621232353-2d01aacdc34a h1:weJVJJRzAJBFRlAiJQROKQs8oC9vOxvm4rZmBBk0ONw=
+github.com/lunixbochs/vtclean v0.0.0-20180621232353-2d01aacdc34a/go.mod h1:pHhQNgMf3btfWnGBVipUOjRYhoOsdGqdm/+2c2E2WMI=
+github.com/manifoldco/promptui v0.8.0 h1:R95mMF+McvXZQ7j1g8ucVZE1gLP3Sv6j9vlF9kyRqQo=
+github.com/manifoldco/promptui v0.8.0/go.mod h1:n4zTdgP0vr0S3w7/O/g98U+e0gwLScEXGwov2nIKuGQ=
+github.com/mattn/go-colorable v0.0.9 h1:UVL0vNpWh04HeJXV0KLcaT7r06gOH2l4OW6ddYRUIY4=
+github.com/mattn/go-colorable v0.0.9/go.mod h1:9vuHe8Xs5qXnSaW/c/ABM9alt+Vo+STaOChaDxuIBZU=
+github.com/mattn/go-isatty v0.0.4 h1:bnP0vzxcAdeI1zdubAl5PjU6zsERjGZb7raWodagDYs=
+github.com/mattn/go-isatty v0.0.4/go.mod h1:M+lRXTBqGeGNdLjl/ufCoiOlB5xdOkqRJdNxMWT7Zi4=
+golang.org/x/sys v0.0.0-20181122145206-62eef0e2fa9b/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

go.sum

@@ -0,0 +1,65 @@
+package main
+
+import (
+	"fmt"
+	"github.com/geekdada/steam-otp/otp"
+	"github.com/jessevdk/go-flags"
+	"github.com/manifoldco/promptui"
+	"os"
+	"strings"
+)
+
+func main() {
+	var options struct {
+		Secret string `short:"s" long:"secret" description:"The shared secret you get from SteamDesktopAuthenticator"`
+	}
+
+	_, err := flags.Parse(&options)
+
+	if err != nil {
+		switch err.(type) {
+		case *flags.Error:
+			fe, _ := err.(*flags.Error)
+			if fe.Type == flags.ErrHelp {
+				os.Exit(0)
+			}
+			fmt.Println(err)
+			os.Exit(1)
+		default:
+			fmt.Println(err)
+			os.Exit(1)
+		}
+	}
+
+	if options.Secret != "" {
+		code, err := otp.GenerateAuthCode(strings.TrimSpace(options.Secret), 0)
+
+		if err != nil {
+			fmt.Printf("Failed to generate code %v\n", err)
+		}
+
+		fmt.Println(code)
+
+		return
+	}
+
+	prompt := promptui.Prompt{
+		Label: "Input the shared secret you get from SteamDesktopAuthenticator",
+		Mask:  '*',
+	}
+
+	result, err := prompt.Run()
+
+	if err != nil {
+		fmt.Printf("Invalid input %v\n", err)
+		return
+	}
+
+	code, err := otp.GenerateAuthCode(strings.TrimSpace(result), 0)
+
+	if err != nil {
+		fmt.Printf("Failed to generate code %v\n", err)
+	}
+
+	fmt.Println(code)
+}

index.js

@@ -0,0 +1,83 @@
+package otp
+
+import (
+	hmac2 "crypto/hmac"
+	"crypto/sha1"
+	"encoding/base64"
+	"encoding/hex"
+	"github.com/funny/binary"
+	"math"
+	"regexp"
+	"time"
+)
+
+/**
+Returns the current local Unix time
+*/
+func getTime(timeOffset int64) int64 {
+	now := time.Now()
+	return now.Unix() + timeOffset
+}
+
+func bufferizeSecret(secret string) (*binary.Buffer, error) {
+	matched, err := regexp.MatchString(`[0-9a-f]{40}`, secret)
+
+	if err != nil {
+		return nil, err
+	}
+
+	if matched {
+		hexValue, err := hex.DecodeString(secret)
+
+		if err != nil {
+			return nil, err
+		} else {
+			return &binary.Buffer{Data: hexValue}, nil
+		}
+	}
+
+	base64Value, err := base64.StdEncoding.DecodeString(secret)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return &binary.Buffer{Data: base64Value}, nil
+}
+
+/**
+Generate a Steam-style TOTP authentication code
+ */
+func GenerateAuthCode(secret string, timeOffset int64) (string, error) {
+	localTime := getTime(timeOffset)
+	secretBuffer, err := bufferizeSecret(secret)
+
+	if err != nil {
+		return "", err
+	}
+
+	buf := binary.Buffer{Data: make([]byte, 8)}
+
+	buf.WriteUint32BE(0)
+	buf.WriteUint32BE(uint32(math.Floor(float64(localTime) / 30)))
+
+	hmac := hmac2.New(sha1.New, secretBuffer.Data)
+	hmac.Write(buf.Data)
+	secretHash := hmac.Sum(nil)
+
+	startPos := secretHash[19] & 0x0F
+	slicedSecretHashBuf := binary.Buffer{Data: secretHash[startPos : startPos + 4]}
+
+	fullCode := slicedSecretHashBuf.ReadUint32BE() & 0x7FFFFFFF
+	chars := "23456789BCDFGHJKMNPQRTVWXY"
+	code := ""
+
+	for i := 0; i < 5; i++ {
+		code += string([]rune(chars)[int(fullCode) % len(chars)])
+		fullCode /= uint32(len(chars))
+	}
+
+	return code, nil
+}
+
+